The enhancement of water solubility of diesel was also evaluated
using biosurfactant An6, in comparison with two other
chemical surfactants, at a concentration of 1 g/L in the presence of
increasing concentration of diesel. As shown in Table 2, no signifi-
cant differences were observed for the percentage of the solubilization
when using 1, 2 and 3% of hydrocarbon. However, a further
increase in diesel concentration affects the solubilization rate.
Indeed, the apparent solubility decreased from 69 to 54.3% when
increasing the concentration from 3 to 4%, respectively. Too high
hydrocarbon quantity could be thus a limiting factor during the
solubilization process. For this purpose, 2% diesel content was
maintained in subsequent work. Further, biosurfactant An6 was
found to be more effective than SDS and Tween 80 in enhancing the
solubility of diesel.